Merge pull request #465 from PyBossa/generalise-importers4

auto-generate list of importers
Merge branch 'master' into culttag-redux
generate importer variant template list
add dummy variant
reorder importers file
allow enumeration of impoerter variant modes
generate list of importer variants from config
restore importer
add PEP8 double blank line around class
Merge pull request #466 from PyBossa/generalise-importers5

Generate importer options template html from config
manual merge
Merge commit 'd84ca' into culttag-redux
manual merge
Merge branch 'master' into culttag-redux